Due to the recent evolution of hardware and software, smart phones, tablet personal computers (PCs), and other types of mobile terminals include not only a cellular wireless communication module based on code division multiple access (CDMA), long term evolution (LTE), or the like but also another type of wireless communication module that uses a wireless local area network (LAN). Communication operators are pursuing deployment of wireless LAN areas as countermeasures against traffic that are rapidly increasing on cellular networks. When a user of a smart phone or tablet PC moves to a wireless LAN area deployed by a network operator, a switchover is possible from cellular communication to wireless LAN communication.
In a technology known in the prior art, when a beacon signal transmitted from an access point on a wireless LAN is received, information about a channel used by the access point is obtained. If an overlap with the frequency band of the channel is found from the information about the channel, it is inferred that there is interference between radio signals transmitted from access points. In another known technology, a terminal is notified of a switchover to prompt it to switch its connection to an access point having a larger reception level.
The followings are reference documents; Japanese Laid-open Patent Publication No. 2005-142893, Japanese Laid-open Patent Publication No. 2006-067178, and Japanese Laid-open Patent Publication No. 2008-263621